(Bloomberg) -- A cargo of chilled natural gas hauled from Louisiana in late December has become a symbol of how global trade is changing for a fuel increasingly seen as a cheap, cleaner-burning option for countries from Latin America to China and India.

The tanker Maran Gas Achilles passed through the Panama Canal and was headed toward Asia at a speed of 20 knots when, suddenly, it made a sharp u-turn in the Pacific. Next stop: Mexico’s Manzanillo terminal on the southwest coast, where it unloaded.

The abrupt route change shows how the U.S., which began shale gas exports just last year, is creating a new paradigm in an industry that once revolved almost entirely around long-term contracts with set destinations. As the new kid on the block, exporters of U.S. liquefied natural gas -- led by Cheniere Energy Inc. and Royal Dutch Shell SA -- are seeking the best price at any given time. As U.S. exports grow, it’s a strategy that could shift the economics of LNG toward an emerging spot market akin to oil.